curl
curl(1) Curl Manual curl(1)
NAME
curl - transfer a URL
SYNOPSIS
curl [options] [URL...]
DESCRIPTION
curl is a tool to transfer data from or to a server, using one of the
supported protocols (HTTP, HTTPS, FTP, FTPS, GOPHER, DICT, TELNET,
LDAP or FILE). The command is designed to work without user interac-
tion.
curl offers a busload of useful tricks like proxy support, user
authentication, ftp upload, HTTP post, SSL (https:) connections, cook-
ies, file transfer resume and more. As you will see below, the amount
of features will make your head spin!
curl is powered by libcurl for all transfer-related features. See
libcurl(3) for details.
URL
The URL syntax is protocol dependent. You’ll find a detailed descrip-
tion in RFC 2396.
You can specify multiple URLs or parts of URLs by writing part sets
within braces as in:
http://site.{one,two,three}.com
or you can get sequences of alphanumeric series by using [] as in:
ftp://ftp.numericals.com/file[1-100].txt
ftp://ftp.numericals.com/file[001-100].txt (with leading zeros)
ftp://ftp.letters.com/file[a-z].txt
No nesting of the sequences is supported at the moment, but you can
use several ones next to each other:
http://any.org/archive[1996-1999]/vol[1-4]/part{a,b,c}.html
You can specify any amount of URLs on the command line. They will be
fetched in a sequential manner in the specified order.
Curl will attempt to re-use connections for multiple file transfers,
so that getting many files from the same server will not do multiple
connects / handshakes. This improves speed. Of course this is only
done on files specified on a single command line and cannot be used
between separate curl invokes.
OPTIONS
-a/--append
(FTP) When used in an FTP upload, this will tell curl to append
to the target file instead of overwriting it. If the file
doesn’t exist, it will be created.
If this option is used twice, the second one will disable
append mode again.
-A/--user-agent <agent string>
(HTTP) Specify the User-Agent string to send to the HTTP
server. Some badly done CGIs fail if its not set to
"Mozilla/4.0". To encode blanks in the string, surround the
string with single quote marks. This can also be set with the
-H/--header option of course.
If this option is set more than once, the last one will be the
one that’s used.
--anyauth
(HTTP) Tells curl to figure out authentication method by
itself, and use the most secure one the remote site claims it
supports. This is done by first doing a request and checking
the response-headers, thus inducing an extra network round-
trip. This is used instead of setting a specific authentication
method, which you can do with --basic, --digest, --ntlm, and
--negotiate. (Added in 7.10.6)
If this option is used several times, the following occurrences
make no difference.
-b/--cookie <name=data>
(HTTP) Pass the data to the HTTP server as a cookie. It is sup-
posedly the data previously received from the server in a "Set-
Cookie:" line. The data should be in the format "NAME1=VALUE1;
NAME2=VALUE2".
If no ’=’ letter is used in the line, it is treated as a file-
name to use to read previously stored cookie lines from, which
should be used in this session if they match. Using this method
also activates the "cookie parser" which will make curl record
incoming cookies too, which may be handy if you’re using this
in combination with the -L/--location option. The file format
of the file to read cookies from should be plain HTTP headers
or the Netscape/Mozilla cookie file format.
NOTE that the file specified with -b/--cookie is only used as
input. No cookies will be stored in the file. To store cookies,
use the -c/--cookie-jar option or you could even save the HTTP
headers to a file using -D/--dump-header!
If this option is set more than once, the last one will be the
one that’s used.
-B/--use-ascii
Use ASCII transfer when getting an FTP file or LDAP info. For
FTP, this can also be enforced by using an URL that ends with
";type=A". This option causes data sent to stdout to be in text
mode for win32 systems.
If this option is used twice, the second one will disable ASCII
usage.
--basic
(HTTP) Tells curl to use HTTP Basic authentication. This is the
default and this option is usually pointless, unless you use it
to override a previously set option that sets a different
authentication method (such as --ntlm, --digest and --negoti-
ate). (Added in 7.10.6)
If this option is used several times, the following occurrences
make no difference.
--ciphers <list of ciphers>
(SSL) Specifies which ciphers to use in the connection. The
list of ciphers must be using valid ciphers. Read up on SSL
cipher list details on this URL:
http://www.openssl.org/docs/apps/ciphers.html
If this option is used several times, the last one will over-
ride the others.
--compressed
(HTTP) Request a compressed response using one of the algo-
rithms libcurl supports, and return the uncompressed document.
If this option is used and the server sends an unsupported
encoding, Curl will report an error.
If this option is used several times, each occurrence will tog-
gle it on/off.
--connect-timeout <seconds>
Maximum time in seconds that you allow the connection to the
server to take. This only limits the connection phase, once
curl has connected this option is of no more use. See also the
-m/--max-time option.
If this option is used several times, the last one will be
used.
-c/--cookie-jar <file name>
Specify to which file you want curl to write all cookies after
a completed operation. Curl writes all cookies previously read
from a specified file as well as all cookies received from
remote server(s). If no cookies are known, no file will be
written. The file will be written using the Netscape cookie
file format. If you set the file name to a single dash, "-",
the cookies will be written to stdout.
NOTE If the cookie jar can’t be created or written to, the
whole curl operation won’t fail or even report an error
clearly. Using -v will get a warning displayed, but that is the
only visible feedback you get about this possibly lethal situa-
tion.
If this option is used several times, the last specfied file
name will be used.
-C/--continue-at <offset>
Continue/Resume a previous file transfer at the given offset.
The given offset is the exact number of bytes that will be
skipped counted from the beginning of the source file before it
is transfered to the destination. If used with uploads, the
ftp server command SIZE will not be used by curl.
Use "-C -" to tell curl to automatically find out where/how to
resume the transfer. It then uses the given output/input files
to figure that out.
If this option is used several times, the last one will be
used.
--create-dirs
When used in conjunction with the -o option, curl will create
the necessary local directory hierarchy as needed. This option
creates the dirs mentioned with the -o option, nothing else. If
the -o file name uses no dir or if the dirs it mentions already
exist, no dir will be created.
To create remote directories when using FTP, try --ftp-create-
dirs.
--crlf (FTP) Convert LF to CRLF in upload. Useful for MVS (OS/390).
If this option is used twice, the second will again disable
crlf converting.
-d/--data <data>
(HTTP) Sends the specified data in a POST request to the HTTP
server, in a way that can emulate as if a user has filled in a
HTML form and pressed the submit button. Note that the data is
sent exactly as specified with no extra processing (with all
newlines cut off). The data is expected to be "url-encoded".
This will cause curl to pass the data to the server using the
content-type application/x-www-form-urlencoded. Compare to
-F/--form. If this option is used more than once on the same
command line, the data pieces specified will be merged together
with a separating &-letter. Thus, using ’-d name=daniel -d
skill=lousy’ would generate a post chunk that looks like
’name=daniel&skill=lousy’.
If you start the data with the letter @, the rest should be a
file name to read the data from, or - if you want curl to read
the data from stdin. The contents of the file must already be
url-encoded. Multiple files can also be specified. Posting data
from a file named ’foobar’ would thus be done with --data @foo-
bar".
To post data purely binary, you should instead use the --data-
binary option.
-d/--data is the same as --data-ascii.
If this option is used several times, the ones following the
first will append data.
--data-ascii <data>
(HTTP) This is an alias for the -d/--data option.
If this option is used several times, the ones following the
first will append data.
--data-binary <data>
(HTTP) This posts data in a similar manner as --data-ascii
does, although when using this option the entire context of the
posted data is kept as-is. If you want to post a binary file
without the strip-newlines feature of the --data-ascii option,
this is for you.
If this option is used several times, the ones following the
first will append data.
--digest
(HTTP) Enables HTTP Digest authentication. This is a authenti-
cation that prevents the password from being sent over the wire
in clear text. Use this in combination with the normal
-u/--user option to set user name and password. See also
--ntlm, --negotiate and --anyauth for related options. (Added
in curl 7.10.6)
If this option is used several times, the following occurrences
make no difference.
--disable-eprt
(FTP) Tell curl to disable the use of the EPRT and LPRT com-
mands when doing active FTP transfers. Curl will normally
always first attempt to use EPRT, then LPRT before using PORT,
but with this option, it will use PORT right away. EPRT and
LPRT are extensions to the original FTP protocol, may not work
on all servers but enable more functionality in a better way
than the traditional PORT command. (Aded in 7.10.5)
If this option is used several times, each occurrence will tog-
gle this on/off.
--disable-epsv
(FTP) Tell curl to disable the use of the EPSV command when
doing passive FTP transfers. Curl will normally always first
attempt to use EPSV before PASV, but with this option, it will
not try using EPSV.
If this option is used several times, each occurrence will tog-
gle this on/off.
-D/--dump-header <file>
Write the protocol headers to the specified file.
This option is handy to use when you want to store the headers
that a HTTP site sends to you. Cookies from the headers could
then be read in a second curl invoke by using the -b/--cookie
option! The -c/--cookie-jar option is however a better way to
store cookies.
When used on FTP, the ftp server response lines are considered
being "headers" and thus are saved there.
If this option is used several times, the last one will be
used.
-e/--referer <URL>
(HTTP) Sends the "Referer Page" information to the HTTP server.
This can also be set with the -H/--header flag of course. When
used with -L/--location you can append ";auto" to the referer
URL to make curl automatically set the previous URL when it
follows a Location: header. The ";auto" string can be used
alone, even if you don’t set an initial referer.
If this option is used several times, the last one will be
used.
--environment
(RISC OS ONLY) Sets a range of environment variables, using the
names the -w option supports, to easier allow extraction of
useful information after having run curl.
If this option is used several times, each occurrence will tog-
gle this on/off.
--egd-file <file>
(HTTPS) Specify the path name to the Entropy Gathering Daemon
socket. The socket is used to seed the random engine for SSL
connections. See also the --random-file option.
-E/--cert <certificate[:password]>
(HTTPS) Tells curl to use the specified certificate file when
getting a file with HTTPS. The certificate must be in PEM for-
mat. If the optional password isn’t specified, it will be
queried for on the terminal. Note that this certificate is the
private key and the private certificate concatenated!
If this option is used several times, the last one will be
used.
--cert-type <type>
(SSL) Tells curl what certificate type the provided certificate
is in. PEM, DER and ENG are recognized types.
If this option is used several times, the last one will be
used.
--cacert <CA certificate>
(HTTPS) Tells curl to use the specified certificate file to
verify the peer. The file may contain multiple CA certificates.
The certificate(s) must be in PEM format.
curl recognizes the environment variable named ’CURL_CA_BUNDLE’
if that is set, and uses the given path as a path to a CA cert
bundle. This option overrides that variable.
The windows version of curl will automatically look for a CA
certs file named ´curl-ca-bundle.crt´, either in the same
directory as curl.exe, or in the Current Working Directory, or
in any folder along your PATH.
If this option is used several times, the last one will be
used.
--capath <CA certificate directory>
(HTTPS) Tells curl to use the specified certificate directory
to verify the peer. The certificates must be in PEM format, and
the directory must have been processed using the c_rehash util-
ity supplied with openssl. Using --capath can allow curl to
make https connections much more efficiently than using --cac-
ert if the --cacert file contains many CA certificates.
If this option is used several times, the last one will be
used.
-f/--fail
(HTTP) Fail silently (no output at all) on server errors. This
is mostly done like this to better enable scripts etc to better
deal with failed attempts. In normal cases when a HTTP server
fails to deliver a document, it returns a HTML document stating
so (which often also describes why and more). This flag will
prevent curl from outputting that and fail silently instead.
If this option is used twice, the second will again disable
silent failure.
--ftp-create-dirs
(FTP) When an FTP URL/operation uses a path that doesn’t cur-
rently exist on the server, the standard behavior of curl is to
fail. Using this option, curl will instead attempt to create
missing directories. (Added in 7.10.7)
If this option is used twice, the second will again disable
silent failure.
--ftp-pasv
(FTP) Use PASV when transfering. PASV is the internal default
behavior, but using this option can be used to override a pre-
vios --ftp-port option. (Added in 7.11.0)
If this option is used twice, the second will again disable
silent failure.
--ftp-ssl
(FTP) Make the FTP connection switch to use SSL/TLS. (Added in
7.11.0)
If this option is used twice, the second will again disable
silent failure.
-F/--form <name=content>
(HTTP) This lets curl emulate a filled in form in which a user
has pressed the submit button. This causes curl to POST data
using the content-type multipart/form-data according to
RFC1867. This enables uploading of binary files etc. To force
the ’content’ part to be be a file, prefix the file name with
an @ sign. To just get the content part from a file, prefix the
file name with the letter <. The difference between @ and < is
then that @ makes a file get attached in the post as a file
upload, while the < makes a text field and just get the con-
tents for that text field from a file.
Example, to send your password file to the server, where ’pass-
word’ is the name of the form-field to which /etc/passwd will
be the input:
curl -F password=@/etc/passwd www.mypasswords.com
To read the file’s content from stdin insted of a file, use -
where the file name should’ve been. This goes for both @ and <
constructs.
You can also tell curl what Content-Type to use for the file
upload part, by using ’type=’, in a manner similar to:
curl -F "web=@index.html;type=text/html" url.com
See further examples and details in the MANUAL.
This option can be used multiple times.
-g/--globoff
This option switches off the "URL globbing parser". When you
set this option, you can specify URLs that contain the letters
{}[] without having them being interpreted by curl itself. Note
that these letters are not normal legal URL contents but they
should be encoded according to the URI standard.
-G/--get
When used, this option will make all data specified with
-d/--data or --data-binary to be used in a HTTP GET request
instead of the POST request that otherwise would be used. The
data will be appended to the URL with a ’?’ separator.
If used in combination with -I, the POST data will instead be
appended to the URL with a HEAD request.
If used multiple times, nothing special happens.
-h/--help
Usage help.
-H/--header <header>
(HTTP) Extra header to use when getting a web page. You may
specify any number of extra headers. Note that if you should
add a custom header that has the same name as one of the inter-
nal ones curl would use, your externally set header will be
used instead of the internal one. This allows you to make even
trickier stuff than curl would normally do. You should not
replace internally set headers without knowing perfectly well
what you’re doing. Replacing an internal header with one with-
out content on the right side of the colon will prevent that
header from appearing.
See also the -A/--user-agent and -e/--referer options.
This option can be used multiple times to add/replace/remove
multiple headers.
-i/--include
(HTTP) Include the HTTP-header in the output. The HTTP-header
includes things like server-name, date of the document, HTTP-
version and more...
If this option is used twice, the second will again disable
header include.
--interface <name>
Perform an operation using a specified interface. You can enter
interface name, IP address or host name. An example could look
like:
curl --interface eth0:1 http://www.netscape.com/
If this option is used several times, the last one will be
used.
-I/--head
(HTTP/FTP/FILE) Fetch the HTTP-header only! HTTP-servers fea-
ture the command HEAD which this uses to get nothing but the
header of a document. When used on a FTP or FILE file, curl
displays the file size and last modification time only.
If this option is used twice, the second will again disable
header only.
-j/--junk-session-cookies
(HTTP) When curl is told to read cookies from a given file,
this option will make it discard all "session cookies". This
will basicly have the same effect as if a new session is
started. Typical browsers always discard session cookies when
they’re closed down. (Added in 7.9.7)
If this option is used several times, each occurrence will tog-
gle this on/off.
-k/--insecure
(SSL) This option explicitly allows curl to perform "insecure"
SSL connections and transfers. Starting with curl 7.10, all SSL
connections will be attempted to be made secure by using the CA
certificate bundle installed by default. This makes all connec-
tions considered "insecure" to fail unless -k/--insecure is
used.
If this option is used twice, the second time will again dis-
able it.
--key <key>
(SSL) Private key file name. Allows you to provide your private
key in this separate file.
If this option is used several times, the last one will be
used.
--key-type <type>
(SSL) Private key file type. Specify which type your --key pro-
vided private key is. DER, PEM and ENG are supported.
If this option is used several times, the last one will be
used.
--krb4 <level>
(FTP) Enable kerberos4 authentication and use. The level must
be entered and should be one of ’clear’, ’safe’, ’confidential’
or ’private’. Should you use a level that is not one of these,
’private’ will instead be used.
This option requiures that the library was built with kerberos4
support. This is not very common. Use -V/--version to see if
your curl supports it.
If this option is used several times, the last one will be
used.
-K/--config <config file>
Specify which config file to read curl arguments from. The con-
fig file is a text file in which command line arguments can be
written which then will be used as if they were written on the
actual command line. Options and their parameters must be spec-
ified on the same config file line. If the parameter is to con-
tain white spaces, the parameter must be inclosed within
quotes. If the first column of a config line is a ’#’ charac-
ter, the rest of the line will be treated as a comment.
Specify the filename as ’-’ to make curl read the file from
stdin.
Note that to be able to specify a URL in the config file, you
need to specify it using the --url option, and not by simply
writing the URL on its own line. So, it could look similar to
this:
url = "http://curl.haxx.se/docs/"
This option can be used multiple times.
--limit-rate <speed>
Specify the maximum transfer rate you want curl to use. This
feature is useful if you have a limited pipe and you’d like
your transfer not use your entire bandwidth.
The given speed is measured in bytes/second, unless a suffix is
appended. Appending ’k’ or ’K’ will count the number as kilo-
bytes, ’m’ or M’ makes it megabytes while ’g’ or ’G’ makes it
gigabytes. Examples: 200K, 3m and 1G.
If you are also using the -Y/--speed-limit option, that option
will take precedence and might cripple the rate-limiting
slightly, to help keeping the speed-limit logic working.
This option was introduced in curl 7.10.
If this option is used several times, the last one will be
used.
-l/--list-only
(FTP) When listing an FTP directory, this switch forces a name-
only view. Especially useful if you want to machine-parse the
contents of an FTP directory since the normal directory view
doesn’t use a standard look or format.
This option causes an FTP NLST command to be sent. Some FTP
servers list only files in their response to NLST; they do not
include subdirectories and symbolic links.
If this option is used twice, the second will again disable
list only.
-L/--location
(HTTP/HTTPS) If the server reports that the requested page has
a different location (indicated with the header line Location:)
this flag will let curl attempt to reattempt the get on the new
place. If used together with -i/--include or -I/--head, headers
from all requested pages will be shown. If authentication is
used, curl will only send its credentials to the initial host,
so if a redirect takes curl to a different host, it won’t
intercept the user+password. See also --location-trusted on how
to change this.
If this option is used twice, the second will again disable
location following.
--location-trusted
(HTTP/HTTPS) Like -L/--location, but will allow sending the
name + password to all hosts that the site may redirect to.
This may or may not introduce a security breach if the site
redirects you do a site to which you’ll send your authentica-
tion info (which is plaintext in the case of HTTP Basic authen-
tication).
If this option is used twice, the second will again disable
location following.
--max-filesize <bytes>
Specify the maximum size (in bytes) of a file to download. If
the file requested is larger than this value, the transfer will
not start and curl will return with exit code 63.
NOTE: The file size is not always known prior to download, and
for such files this option has no effect even if the file
transfer ends up being larger than this given limit. This con-
cerns both FTP and HTTP transfers.
-m/--max-time <seconds>
Maximum time in seconds that you allow the whole operation to
take. This is useful for preventing your batch jobs from hang-
ing for hours due to slow networks or links going down. This
doesn’t work fully in win32 systems. See also the --connect-
timeout option.
If this option is used several times, the last one will be
used.
-M/--manual
Manual. Display the huge help text.
-n/--netrc
Makes curl scan the .netrc file in the user’s home directory
for login name and password. This is typically used for ftp on
unix. If used with http, curl will enable user authentication.
See netrc(4) or ftp(1) for details on the file format. Curl
will not complain if that file hasn’t the right permissions (it
should not be world nor group readable). The environment vari-
able "HOME" is used to find the home directory.
A quick and very simple example of how to setup a .netrc to
allow curl to ftp to the machine host.domain.com with user name
’myself’ and password
machine host.domain.com login myself password secret
If this option is used twice, the second will again disable
netrc usage.
--netrc-optional
Very similar to --netrc, but this option makes the .netrc usage
optional and not mandatory as the --netrc does.
--negotiate
(HTTP) Enables GSS-Negotiate authentication. The GSS-Negotiate
method was designed by Microsoft and is used in their web
aplications. It is primarily meant as a support for Kerberos5
authentication but may be also used along with another authen-
tication methods. For more information see IETF draft draft-
brezak-spnego-http-04.txt. (Added in 7.10.6)
This option requiures that the library was built with GSSAPI
support. This is not very common. Use -V/--version to see if
your version supports GSS-Negotiate.
If this option is used several times, the following occurrences
make no difference.
-N/--no-buffer
Disables the buffering of the output stream. In normal work
situations, curl will use a standard buffered output stream
that will have the effect that it will output the data in
chunks, not necessarily exactly when the data arrives. Using
this option will disable that buffering.
If this option is used twice, the second will again switch on
buffering.
--ntlm (HTTP) Enables NTLM authentication. The NTLM authentication
method was designed by Microsoft and is used by IIS web
servers. It is a proprietary protocol, reversed engineered by
clever people and implemented in curl based on their efforts.
This kind of behavior should not be endorsed, you should
encourage everyone who uses NTLM to switch to a public and doc-
umented authentication method instead. Such as Digest. (Added
in 7.10.6)
If you want to enable NTLM for your proxy authentication, then
use --proxy-ntlm.
This option requiures that the library was built with SSL sup-
port. Use -V/--version to see if your curl supports NTLM.
If this option is used several times, the following occurrences
make no difference.
-o/--output <file>
Write output to <file> instead of stdout. If you are using {}
or [] to fetch multiple documents, you can use ’#’ followed by
a number in the <file> specifier. That variable will be
replaced with the current string for the URL being fetched.
Like in:
curl http://{one,two}.site.com -o "file_#1.txt"
or use several variables like:
curl http://{site,host}.host[1-5].com -o "#1_#2"
You may use this option as many times as you have number of
URLs.
See also the --create-dirs option to create the local directo-
ries dynamically.
-O/--remote-name
Write output to a local file named like the remote file we get.
(Only the file part of the remote file is used, the path is cut
off.)
You may use this option as many times as you have number of
URLs.
--pass <phrase>
(SSL) Pass phrase for the private key
If this option is used several times, the last one will be
used.
--proxy-basic
Tells curl to use HTTP Basic authentication when communicating
with the given proxy. Use --basic for enabling HTTP Basic with
a remote host. Basic is the default authentication method curl
uses with proxies.
If this option is used twice, the second will again disable
proxy HTTP Basic authentication.
--proxy-digest
Tells curl to use HTTP Digest authentication when communicating
with the given proxy. Use --digest for enabling HTTP Digest
with a remote host.
If this option is used twice, the second will again disable
proxy HTTP Digest.
--proxy-ntlm
Tells curl to use HTTP NTLM authentication when communicating
with the given proxy. Use --ntlm for enabling NTLM with a
remote host.
If this option is used twice, the second will again disable
proxy HTTP NTLM.
-p/--proxytunnel
When an HTTP proxy is used (-x/--proxy), this option will cause
non-HTTP protocols to attempt to tunnel through the proxy
instead of merely using it to do HTTP-like operations. The tun-
nel approach is made with the HTTP proxy CONNECT request and
requires that the proxy allows direct connect to the remote
port number curl wants to tunnel through to.
If this option is used twice, the second will again disable
proxy tunnel.
-P/--ftp-port <address>
(FTP) Reverses the initiator/listener roles when connecting
with ftp. This switch makes Curl use the PORT command instead
of PASV. In practice, PORT tells the server to connect to the
client’s specified address and port, while PASV asks the server
for an ip address and port to connect to. <address> should be
one of:
interface
i.e "eth0" to specify which interface’s IP address you
want to use (Unix only)
IP address
i.e "192.168.10.1" to specify exact IP number
host name
i.e "my.host.domain" to specify machine
- (any single-letter string) to make it pick the machine’s
default
If this option is used several times, the last one will be used. Dis-
able the use of PORT with --ftp-pasv. Disable the attempt to use the
EPRT command instead of PORT by using --disable-eprt. EPRT is really
PORT++.
-q If used as the first parameter on the command line, the
$HOME/.curlrc file will not be read and used as a config file.
-Q/--quote <comand>
(FTP) Send an arbitrary command to the remote FTP server. Quote
commands are sent BEFORE the transfer is taking place. To make
commands take place after a successful transfer, prefix them
with a dash ’-’. You may specify any amount of commands to be
run before and after the transfer. If the server returns fail-
ure for one of the commands, the entire operation will be
aborted. You must send syntactically correct FTP commands as
RFC959 defines.
This option can be used multiple times.
--random-file <file>
(HTTPS) Specify the path name to file containing what will be
considered as random data. The data is used to seed the random
engine for SSL connections. See also the --egd-file option.
-r/--range <range>
(HTTP/FTP) Retrieve a byte range (i.e a partial document) from
a HTTP/1.1 or FTP server. Ranges can be specified in a number
of ways.
0-499 specifies the first 500 bytes
500-999 specifies the second 500 bytes
-500 specifies the last 500 bytes
9500 specifies the bytes from offset 9500 and forward
0-0,-1 specifies the first and last byte only(*)(H)
500-700,600-799
specifies 300 bytes from offset 500(H)
100-199,500-599
specifies two separate 100 bytes ranges(*)(H)
(*) = NOTE that this will cause the server to reply with a multipart
response!
You should also be aware that many HTTP/1.1 servers do not have this
feature enabled, so that when you attempt to get a range, you’ll
instead get the whole document.
FTP range downloads only support the simple syntax ’start-stop’
(optionally with one of the numbers omitted). It depends on the non-
RFC command SIZE.
If this option is used several times, the last one will be used.
-R/--remote-time
When used, this will make libcurl attempt to figure out the
timestamp of the remote file, and if that is available make the
local file get that same timestamp.
If this option is used twice, the second time disables this
again.
-s/--silent
Silent mode. Don’t show progress meter or error messages.
Makes Curl mute.
If this option is used twice, the second will again disable
mute.
-S/--show-error
When used with -s it makes curl show error message if it fails.
If this option is used twice, the second will again disable
show error.
--socks <host[:port]>
Use the specified SOCKS5 proxy. If the port number is not spec-
ified, it is assumed at port 1080. (Option added in 7.11.1)
This option overrides any previous use of -x/--proxy, as they
are mutually exclusive.
If this option is used several times, the last one will be
used.
--stderr <file>
Redirect all writes to stderr to the specified file instead. If
the file name is a plain ’-’, it is instead written to stdout.
This option has no point when you’re using a shell with decent
redirecting capabilities.
If this option is used several times, the last one will be
used.
--tcp-nodelay
Turn on the TCP_NODELAY option. See the curl_easy_setopt(3) man
page for details about this option. (Added in 7.11.2)
If this option is used several times, each occurance toggles
this on/off.
-t/--telnet-option <OPT=val>
Pass options to the telnet protocol. Supported options are:
TTYPE=<term> Sets the terminal type.
XDISPLOC=<X display> Sets the X display location.
NEW_ENV=<var,val> Sets an environment variable.
-T/--upload-file <file>
This transfers the specified local file to the remote URL. If
there is no file part in the specified URL, Curl will append
the local file name. NOTE that you must use a trailing / on the
last directory to really prove to Curl that there is no file
name or curl will think that your last directory name is the
remote file name to use. That will most likely cause the upload
operation to fail. If this is used on a http(s) server, the PUT
command will be used.
Use the file name "-" (a single dash) to use stdin instead of a
given file.
Before 7.10.8, when this option was used several times, the
last one was used.
In curl 7.10.8 and later, you can specify one -T for each URL
on the command line. Each -T + URL pair specifies what to
upload and to where. curl also supports "globbing" of the -T
argument, meaning that you can upload multiple files to a sin-
gle URL by using the same URL globbing style supported in the
URL, like this:
curl -T "{file1,file2}" http://www.uploadtothissite.com
or even
curl -T "img[1-1000].png" ftp://ftp.picturemania.com/upload/
--trace <file>
Enables a full trace dump of all incoming and outgoing data,
including descriptive information, to the given output file.
Use "-" as filename to have the output sent to stdout.
If this option is used several times, the last one will be
used. (Added in 7.9.7)
--trace-ascii <file>
Enables a full trace dump of all incoming and outgoing data,
including descriptive information, to the given output file.
Use "-" as filename to have the output sent to stdout.
This is very similar to --trace, but leaves out the hex part
and only shows the ASCII part of the dump. It makes smaller
output that might be easier to read for untrained humans.
If this option is used several times, the last one will be
used. (Added in 7.9.7)
-u/--user <user:password>
Specify user and password to use for server authentication.
If this option is used several times, the last one will be
used.
-U/--proxy-user <user:password>
Specify user and password to use for proxy authentication.
If this option is used several times, the last one will be
used.
--url <URL>
Specify a URL to fetch. This option is mostly handy when you
want to specify URL(s) in a config file.
This option may be used any number of times. To control where
this URL is written, use the -o/--output or the -O/--remote-
name options.
-v/--verbose
Makes the fetching more verbose/talkative. Mostly usable for
debugging. Lines starting with ’>’ means data sent by curl, ’<’
means data received by curl that is hidden in normal cases and
lines starting with ’*’ means additional info provided by curl.
Note that if you want to see HTTP headers in the output,
-i/--include might be option you’re looking for.
If you think this option still doesn’t give you enough details,
consider using --trace or --trace-ascii instead.
If this option is used twice, the second will again disable
verbose.
-V/--version
Displays information about curl and the libcurl version it
uses.
The first line includes the full version of curl, libcurl and
other 3rd party libraries linked with the executable.
The second line (starts with "Protocols:") shows all protocols
that libcurl reports to support.
The third line (starts with "Features:") shows specific fea-
tures libcurl reports to offer. Available features include:
IPv6 You can use IPv6 with this.
krb4 Krb4 for ftp is supported.
SSL HTTPS and FTPS are supported.
libz Automatic decompression of compressed files over HTTP is
supported.
NTLM NTLM authenticaion is supported.
GSS-Negotiate
Negotiate authenticaion is supported.
Debug This curl uses a libcurl built with Debug. This enables
more error-tracking and memory debugging etc. For curl-
developers only!
AsynchDNS
This curl uses asynchronous name resolves.
SPNEGO SPNEGO Negotiate authenticaion is supported.
Largefile
This curl supports transfers of large files, files
larger than 2GB.
IDN This curl supports IDN - international domain names.
-w/--write-out <format>
Defines what to display after a completed and successful opera-
tion. The format is a string that may contain plain text mixed
with any number of variables. The string can be specified as
"string", to get read from a particular file you specify it
"@filename" and to tell curl to read the format from stdin you
write "@-".
The variables present in the output format will be substituted
by the value or text that curl thinks fit, as described below.
All variables are specified like %{variable_name} and to output
a normal % you just write them like %%. You can output a new-
line by using \n, a carriage return with \r and a tab space
with \t.
NOTE: The %-letter is a special letter in the win32-environ-
ment, where all occurrences of % must be doubled when using
this option.
Available variables are at this point:
url_effective The URL that was fetched last. This is mostly
meaningful if you’ve told curl to follow loca-
tion: headers.
http_code The numerical code that was found in the last
retrieved HTTP(S) page.
time_total The total time, in seconds, that the full opera-
tion lasted. The time will be displayed with
millisecond resolution.
time_namelookup
The time, in seconds, it took from the start
until the name resolving was completed.
time_connect The time, in seconds, it took from the start
until the connect to the remote host (or proxy)
was completed.
time_pretransfer
The time, in seconds, it took from the start
until the file transfer is just about to begin.
This includes all pre-transfer commands and
negotiations that are specific to the particular
protocol(s) involved.
time_starttransfer
The time, in seconds, it took from the start
until the first byte is just about to be trans-
fered. This includes time_pretransfer and also
the time the server needs to calculate the
result.
size_download The total amount of bytes that were downloaded.
size_upload The total amount of bytes that were uploaded.
size_header The total amount of bytes of the downloaded
headers.
size_request The total amount of bytes that were sent in the
HTTP request.
speed_download The average download speed that curl measured
for the complete download.
speed_upload The average upload speed that curl measured for
the complete upload.
content_type The Content-Type of the requested document, if
there was any. (Added in 7.9.5)
If this option is used several times, the last one will be used.
-x/--proxy <proxyhost[:port]>
Use specified HTTP proxy. If the port number is not specified,
it is assumed at port 1080.
This option overrides existing environment variables that sets
proxy to use. If there’s an environment variable setting a
proxy, you can set proxy to "" to override it.
Note that all operations that are performed over a HTTP proxy
will transparantly be converted to HTTP. It means that certain
protocol specific operations might not be available. This is
not the case if you can tunnel through the proxy, as done with
the -p/--proxytunnel option.
If this option is used several times, the last one will be
used.
-X/--request <command>
(HTTP) Specifies a custom request to use when communicating
with the HTTP server. The specified request will be used
instead of the standard GET. Read the HTTP 1.1 specification
for details and explanations.
(FTP) Specifies a custom FTP command to use instead of LIST
when doing file lists with ftp.
If this option is used several times, the last one will be
used.
-y/--speed-time <time>
If a download is slower than speed-limit bytes per second dur-
ing a speed-time period, the download gets aborted. If speed-
time is used, the default speed-limit will be 1 unless set with
-y.
This option controls transfers and thus will not affect slow
connects etc. If this is a concern for you, try the --connect-
timeout option.
If this option is used several times, the last one will be
used.
-Y/--speed-limit <speed>
If a download is slower than this given speed, in bytes per
second, for speed-time seconds it gets aborted. speed-time is
set with -Y and is 30 if not set.
If this option is used several times, the last one will be
used.
-z/--time-cond <date expression>
(HTTP) Request to get a file that has been modified later than
the given time and date, or one that has been modified before
that time. The date expression can be all sorts of date strings
or if it doesn’t match any internal ones, it tries to get the
time from a given file name instead! See the GNU date(1) or
curl_getdate(3) man pages for date expression details.
Start the date expression with a dash (-) to make it request
for a document that is older than the given date/time, default
is a document that is newer than the specified date/time.
If this option is used several times, the last one will be
used.
-Z/--max-redirs <num>
Set maximum number of redirection-followings allowed. If
-L/--location is used, this option can be used to prevent curl
from following redirections "in absurdum".
If this option is used several times, the last one will be
used.
-0/--http1.0
(HTTP) Forces curl to issue its requests using HTTP 1.0 instead
of using its internally preferred: HTTP 1.1.
-1/--tlsv1
(HTTPS) Forces curl to use TSL version 1 when negotiating with
a remote TLS server.
-2/--sslv2
(HTTPS) Forces curl to use SSL version 2 when negotiating with
a remote SSL server.
-3/--sslv3
(HTTPS) Forces curl to use SSL version 3 when negotiating with
a remote SSL server.
-4/--ipv4
If libcurl is capable of resolving an address to multiple IP
versions (which it is if it is ipv6-capable), this option tells
libcurl to resolve names to IPv4 addresses only. (Added in
7.10.8)
-6/--ipv6
If libcurl is capable of resolving an address to multiple IP
versions (which it is if it is ipv6-capable), this option tells
libcurl to resolve names to IPv6 addresses only. (Added in
7.10.8)
-#/--progress-bar
Make curl display progress information as a progress bar
instead of the default statistics.
If this option is used twice, the second will again disable the
progress bar.
FILES
~/.curlrc
Default config file.
ENVIRONMENT
http_proxy [protocol://]<host>[:port]
Sets proxy server to use for HTTP.
HTTPS_PROXY [protocol://]<host>[:port]
Sets proxy server to use for HTTPS.
FTP_PROXY [protocol://]<host>[:port]
Sets proxy server to use for FTP.
GOPHER_PROXY [protocol://]<host>[:port]
Sets proxy server to use for GOPHER.
ALL_PROXY [protocol://]<host>[:port]
Sets proxy server to use if no protocol-specific proxy is set.
NO_PROXY <comma-separated list of hosts>
list of host names that shouldn’t go through any proxy. If set
to a asterisk
EXIT CODES
There exists a bunch of different error codes and their corresponding
error messages that may appear during bad conditions. At the time of
this writing, the exit codes are:
1 Unsupported protocol. This build of curl has no support for
this protocol.
2 Failed to initialize.
3 URL malformat. The syntax was not correct.
4 URL user malformatted. The user-part of the URL syntax was not
correct.
5 Couldn’t resolve proxy. The given proxy host could not be
resolved.
6 Couldn’t resolve host. The given remote host was not resolved.
7 Failed to connect to host.
8 FTP weird server reply. The server sent data curl couldn’t
parse.
9 FTP access denied. The server denied login.
10 FTP user/password incorrect. Either one or both were not
accepted by the server.
11 FTP weird PASS reply. Curl couldn’t parse the reply sent to the
PASS request.
12 FTP weird USER reply. Curl couldn’t parse the reply sent to the
USER request.
13 FTP weird PASV reply, Curl couldn’t parse the reply sent to the
PASV request.
14 FTP weird 227 format. Curl couldn’t parse the 227-line the
server sent.
15 FTP can’t get host. Couldn’t resolve the host IP we got in the
227-line.
16 FTP can’t reconnect. Couldn’t connect to the host we got in the
227-line.
17 FTP couldn’t set binary. Couldn’t change transfer method to
binary.
18 Partial file. Only a part of the file was transfered.
19 FTP couldn’t download/access the given file, the RETR (or simi-
lar) command failed.
20 FTP write error. The transfer was reported bad by the server.
21 FTP quote error. A quote command returned error from the
server.
22 HTTP page not retrieved. The requested url was not found or
returned another error with the HTTP error code being 400 or
above. This return code only appears if -f/--fail is used.
23 Write error. Curl couldn’t write data to a local filesystem or
similar.
24 Malformed user. User name badly specified.
25 FTP couldn’t STOR file. The server denied the STOR operation,
used for FTP uploading.
26 Read error. Various reading problems.
27 Out of memory. A memory allocation request failed.
28 Operation timeout. The specified time-out period was reached
according to the conditions.
29 FTP couldn’t set ASCII. The server returned an unknown reply.
30 FTP PORT failed. The PORT command failed. Not all FTP servers
support the PORT command, try doing a transfer using PASV
instead!
31 FTP couldn’t use REST. The REST command failed. This command is
used for resumed FTP transfers.
32 FTP couldn’t use SIZE. The SIZE command failed. The command is
an extension to the original FTP spec RFC 959.
33 HTTP range error. The range "command" didn’t work.
34 HTTP post error. Internal post-request generation error.
35 SSL connect error. The SSL handshaking failed.
36 FTP bad download resume. Couldn’t continue an earlier aborted
download.
37 FILE couldn’t read file. Failed to open the file. Permissions?
38 LDAP cannot bind. LDAP bind operation failed.
39 LDAP search failed.
40 Library not found. The LDAP library was not found.
41 Function not found. A required LDAP function was not found.
42 Aborted by callback. An application told curl to abort the
operation.
43 Internal error. A function was called with a bad parameter.
44 Internal error. A function was called in a bad order.
45 Interface error. A specified outgoing interface could not be
used.
46 Bad password entered. An error was signaled when the password
was entered.
47 Too many redirects. When following redirects, curl hit the max-
imum amount.
48 Unknown TELNET option specified.
49 Malformed telnet option.
51 The remote peer’s SSL certificate wasn’t ok
52 The server didn’t reply anything, which here is considered an
error.
53 SSL crypto engine not found
54 Cannot set SSL crypto engine as default
55 Failed sending network data
56 Failure in receiving network data
57 Share is in use (internal error)
58 Problem with the local certificate
59 Couldn’t use specified SSL cipher
60 Problem with the CA cert (path? permission?)
61 Unrecognized transfer encoding
62 Invalid LDAP URL
63 Maximum file size exceeded
XX There will appear more error codes here in future releases. The
existing ones are meant to never change.
AUTHORS / CONTRIBUTORS
Daniel Stenberg is the main author, but the whole list of contributors
is found in the separate THANKS file.
WWW
http://curl.haxx.se
FTP
ftp://ftp.sunet.se/pub/www/utilities/curl/
SEE ALSO
ftp(1), wget(1), snarf(1)
Curl 7.12 3 May 2004 curl(1)
